The present invention relates generally to forage harvesters and, more particularly, to a discharge spout control device.
Generally, forage harvesters chop crop material into relatively small particles for storage and subsequent feeding to livestock. Precision type forage harvesters generally include a rotating cutterhead having a plurality of knives mounted thereon. Crop material is fed across a stationary shear bar which cooperates with the rotating cutterhead knives to cut the crop material into relatively small particles by a shearing action. The reduced crop material is normally conveyed to a rotary forage blower which engages the reduced crop material and imparts sufficient energy thereto for discharge thereof upwardly and rearwardly through a spout which directs the flow of crop material into a trailing storage vehicle.
Normally, the forage blower is inclined in a vertically oriented plane and includes an upwardly directed discharge tube. The discharge deflection spout is rotatably mounted on the discharge tube and is curved so that the crop material is discharged in a substantially horizontal direction. A rotation mechanism is connected to the spout for rotation thereof to direct the flow of discharge crop material in the desired direction.
As can be seen in Application for U.S. Pat. Ser. No. 026,499, entitled "Forage Harvester," filed Apr. 3, 1979 in the names of E. H. Priepke and R. A. Wagstaff and issued on Sept. 23, 1980 as U.S. Pat. No. 4,223,846, the blower can be tilted out of its normally vertical plane and positioned at least partially underneath the cutterhead to eliminate the need for a separate conveying device between the cutterhead and the blower. However, tilting the plane of the blower out of its normal vertical alignment creates a problem of maintaining a horizontal disposition of the discharge end of the spout upon rotation thereof. Rotating the spout about an axis inclined to the vertical results in the discharge end swinging in an arc inclined from a horizontal plane; therefore, the discharge end of the spout would be moving vertically relative to the ground upon rotation thereof about the discharge tube of the blower.
It is desirable to maintain the flow of discharge crop material at approximately the same elevation so that it can be efficiently directed into the trailing storage vehicle. Furthermore, it is desirable to provide a simple means of adjusting the vertical height of the discharge end of the spout relative to the ground to accommodate various sizes of trailing storage vehicles. Another problem with existing harvester spout control devices is a tendency for the various components to bind while the spout is rotating and, thereby, require heavy forces to rotate the spout.